Hydraulic valving for pressure applying units



Jan. 6, 1959 c. E. HOLT 2,867,087

HYDRAUL IC VALVING FOR PRESSURE APPLYING UNITS Filed Nov. 5, 1956 m L's-m: mu m. 5& a z

United States Patent C F HYDRAULIC VALVING FOR PRESSURE APPLYING UNITS Clare E. Holt, Fox Point, Wis., assignor to Blackhawk Mfg. Co., Milwaukee, Wis., a corporation of Wisconsin Application November 5, 1956, Serial N 0. 620,292

1 Claim. (Cl. 60-52) The present invention relates generally to improvements in the art of hydraulics, and relates more particularly to improvements in the valving and fluid circuitry of power applying devices such as hydraulic jacks.

A primary object of the invention is to provide an improved hydraulically operable pressure applying unit which is extremely simple and compact in construction and which is moreover highly efficient in actual use and capable of being readily manufactured at low cost.

Still another specific object of my present invention is to provide a novel and improved valving arrangement for hydraulically operable power devices in which the number and length of fluid passageways required for the performance of the pumping and distribution functions are reduced to a minimum.

A further specific object of the present invention is to provide an improved hydraulic jack having a unitary base which houses the entire power circuitry for the jack and including the power piston and the pressure release valve which are located in a common plane with the valve port intersecting the piston chamber thereby minimizing the number of fluid passageways required, reducing the number of machining operations and resultant fabrication costs, facilitating reduction in size and weight of the unit, and permitting more ready inspection and assembly of parts.

An additional specific object of the present invention is to provide an improved hydraulic power unit embodying a base housing the fluid distributing pump and in which the pump inlet and outlet ports as well as the inlet and outlet distributing valves and the longitudinally movable release valve all lie in a single plane common to that of the pump and with the release valve axis being angularly disposed with respect to the axis of the pump plunger.

These and other specific objects and advantages of the invention will become apparent from the following detailed description.

A clear conception of the several features constituting the present improvement, and of the mode of constructing and of utilizing a typical hydraulic jack embodying the invention, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a side view of a typical hydraulically operable lifting jack embodying the present invention;

Fig. 2 is a transverse horizontal section through the base of the jack taken along the line 22 of Fig. 1;

Fig. 3 is a fragmentary transverse vertical section taken along the line 33 of Fig. 2; and

Fig. 4 is another fragmentary transverse vertical section taken along the irregular line 44 of Fig. 2.

While the invention has been particularly shown and described herein as being embodied in and especially applicable to hydraulically operable vehicle lifting jacks having an upwardly projecting displacement chamber surrounded by an annular liquid supply reservoir, it is not de- 2,867,087 Patented Jan. 6, 1959 sired or intended to unnecessarily limit or restrict the utility of the invention by reason of such specific embodiment since the improvements may obviously be incorporated with equal advantage in various types of hydraulically operated power units. It is also contemplated that certain specific descriptive terms used herein shall be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawing, the hydraulic jack shown therein as a typical example of a power device in which the invention is embodied to advantages comprises, in general, a unitary base 6 preferably of cylindrical form and having all of the fluid distributing valves and power circuitry for the device formed therein in accordance with the invention as will hereinafter more fully appear, a tube 7 secured to the base coaxially thereof and projecting upwardly therefrom to form a power cylinder or displacement chamber 8 housing a reciprocable work-performing piston or ram 9 therein, an outer tubular member 10 of somewhat larger internal diameter than the outer diam eter of the tube 7 surrounding and spaced from the tube and coaxially secured to and likewise projecting upwardly from the base 6 to provide an annular liquid supply reservoir 11, the tube 10 being flanged inwardly at its upper end and secured to the tube 7 to seal the reservoir 11, a suitable work-engaging member or saddle 12 secured to the upper end of the ram 9 for supporting desired loads, and a ground engaging base plate 13 suitably secured to the unitary base 6 for affording stability to the unit in use.

In accordance with the present invention, the unitary base 6 is provided with a substantially horizontal bore 15 extending transversely of the axis of the upwardly projecting power cylinder 8 and forming a displacement chamber for a pump plunger 16 reciprocable therein, the bore 15 having inlet and outlet ports 17, 18 respectively communicating therewith in a plane common to that of the bore axis and preferably at or near the inner end of the bore. The base 6 is furthermore provided with liquid flow control valves 19, 20 in the respective ports 17, 18 and also lying in the plane of the bore axis, the inlet port 17 being connected with the reservoir 11 in advance of the inlet valve 19 by a passage 21 extending upwardly through the base from the inlet port, and the outlet port 18 beyond the outlet valve 20 being connected with the lower end of the displacement chamber or power cylinder 8 by another upwardly extending passage 22. The base 6 is furthermore provided with a threaded opening 23 for adjustably receiving the stem of a release valve 24 which is longitudinally movable in an obvious manner along an axis angularly disposed with respect i0 the bore 15 and also lying in a plane common to that of the bore 15 and the valve 20 to selectively open and close another upwardly extending passage 25 in the base 6 which is adapted to connect the cylinder 8 directly with the reservoir 11 independently of the inlet and outlet ports when the release valve 24 is opened as will hereinafter more fully appear. To permit access to the reservoir 11 for filling the same with operating fluid, the base 6 may also be provided with a bore 26 extending upwardly entirely through the base to the lower end of the reservoir 11, the bore 26 being provided with a removable threaded plug 27 for closing the bore 26 after the reservoir has been supplied with the proper amount of fluid.

As shown, the base consists of a solid unitary block of bar stock or the like preferably of cylindrical form, and the various passage-ways, ports, valve receiving and housing opening and pump displacement chamber may all be formed in an obvious manner by means of drilling or boring operations. The valves 19, 20 may be of the ball type as shown, and the ball 19 is preferably confined with the inlet port 17 by means of a screen 29 or the like seated within the inner end of the bore forming the pump displacement chamber, while the ball may be normally maintained against its seat to close the port 18 as by means of a spring or the like cooperating with the inner end of the valve 24. The pump plunger 16 may be surrounded by a suitable seal 31 to prevent the escape of operating fluid from within the pump chamber formed by the bore 15, and the pump piston is operable as by means of a lever 32 swingable by means of the handle portion 33 about a pivot pin 34 supported by a lug or lugs 35 secured to the outer tubular member 10 in a suitable manner, the lever 32 being loosely connected to the outer end of the pump piston 16 as by means of a clamping element 36 pivotally carried as at 37 by the swinging end of the lever. The longitudinally movable valve 24 is also preferably pro vided with a gripping and manipulating handle element 38 and extends into the base 6 from the same side as the pump plunger 16 so as to facilitate manipulation of the entire hydraulic assemblage, and if necessary, the valve may also be sealed in a suitable manner so as to prevent escape of fluid.

In operation, the reservoir 11 is first provided with a suitable amount of operating fluid supplied thereto by way of the bore or passage 26 which is thereafter capped. The jack may then be placed in the usual manner under the load to be lifted, and the pump piston 16 is reciprocated 'by means of the lever 32 in a usual manner. As the piston 16 is withdrawn in an outward direction from the pump cavity or displacement chamber formed by the bore 15, the ball valve 19 is withdrawn from its seat as shown in Fig. 2 by means of the diflerential pressure created between the reservoir 11 and the pump chamber, the ball valve 19 being prevented from withdrawal into the pump chamber by means of the screen 29. During the suction stroke of the piston 16, the ball valve 20 is retained against its seat by virtue of the low pressure existing in the pump chamber as well as by the action of the spring 30, but as the pump piston is moved on the return stroke toward the inner end of the bore 15, the valve 19 is reseated by reason of the high pressure within the pump displacement chamber and the valve 20 is forced open to admit fluid under pressure to the passage 22 and the lower end of the piston displacement chamber 8 to thereby cause the piston 9 to rise and lift the load. This action is repeated in an obvious manner until the load resting on the saddle 12 has been raised to the desired height. When it is desired to relieve the pressure from the lower end of the displacement chamber 3 to permit lowering of the ram or piston 9. it is only necessary to back the valve 24 from its seat within the opening 23 a sufficient distance to uncover the passage-Way 25 and thereby vent the lower end of the displacement chamber 8 to the reservoir 11 through the passages 22, 25.

From the foregoing detailed description, it is believed apparent that the improved device embodying the novel monoplane valve and fluid distributing arrangement results in an extremely simple and compact structure. The various ports, passage-ways and pump displacement chamber may all be conveniently'formed within the base 6 with the aid of available machine tools, and the improved unit may be readily assembled in an obvious manner with the tubular members 7 and 10 being secured to the base by welding or the like. The provision of the pump displacement chamber formed by the bore 15, pump inlet and outlet ports 17, 18 respectively, inlet and outlet valves 19, 20 respectively and the release valve 24 all in a common plane results in reduction in overall size and weight of the device, economy in fabrication as well as materials, and reduction in the number and the length of the various passage-ways. The improved device is exceptionally rapid in responding to the actuation of the pump piston by means of the operating lever 32, and the valve 24 is conveniently accessible for ready manipulation from the same side of the device as the pump. It is, of course, obvious that the improvement may be embodied with equal advantage in diverse hydraulically actuated power applying devices, and all parts of the unit are readily accessible for inspection, replacement or repair.

It is not desired or intended to limit or restrict the present invention to the exact details of construction or to the precise mode of use herein shown and described since various modifications within the scope of the appended claim may occur to persons skilled in the art to which this invention pertains.

I claim:

In a hydraulic power unit, a unitary base supporting a power cylinder and a liquid supply reservoir and being provided with a main bore extending laterally of the cylinder axis into said base from one side only thereof for a major portion of the width of said base, the inner end of said bore 'being provided with a reduced portion in axial alinement therewith and in turn communicating with said reservoir remote from said main bore through an inlet passage formed in said base, an inlet valve housed within said reduced portion of the main bore, said base also being provided with an auxiliary transverse bore extending into said base from one side thereof in the same plane as that of said main bore and with its axis intersecting the axis of said main bore at an acute angle, the inner end of said auxiliary bore communicating with the inner end of said main bore through a reduced extension of said auxiliary bore formed in said base in axial alinement with said auxiliary bore and intersecting said main bore, an outlet valve housed within said auxiliary bore and normally seated against the reduced extension thereof to close the same, said auxiliary bore being in open communication with said power cylinder through an outlet passage formed in said base and also being adapted to be placed in communication with said reservoir through a release passage formed in said base, a release valve received in and movable along said auxiliary bore toward and away from the reduced extension thereof and across said release passage for closing and opening the same, and a pump plunger reciprocable within said main bore to successively draw liquid from said reservoir past said inlet valve and force the same to said power cylinder past said outlet valve.

References Cited in the file of this patent UNITED STATES PATENTS 2,085,111 McConnell June 29, 1937 2,577,539 Page Dec. 4, 1951 2,618,929 Bidin Nov. 25, 1952 

